Refining of petroleum hydrocarbon waxes



Patented Jan. 15, 1946 u ner'mmo'for'rnrnomum m ann s 1 Anthony Kinsel, Petrolia, Pa.,-. assignon to,tL.?-" e Sonneborn Sons, Inc a corporation of Dela- No Drawing.

Application September 1, 1944, Serial-No. 552,389

70mins (cries-52.1);

This invention relates to new and useful improvements in the refining of petroleum residual waxes. v *In the conventional refining of raw petroleum residual waxes, the refining treatment includes the steps of melting the raw material and filtering the molten product through suitable adsorbents. With certain types of raw stocks, however, relatively low filtration yields are obtained. For the purpose of increasing the filtration" yields of such stocks the molten product is first treated with aluminum chloride before filtering the same. In this manner filtration yields are considerably increased; The aluminum .chloride treatment; however, will impart to the resulting product cor rosive properties due to the presence 'of'organicchlorides and aluminum chloride hydrocarbon complexes and/ or the decompositionproducts thereof. Attempts have been repeatedly made to eliminate o ameliorate this drawback of aluminum chloride treatment by, for instance-the addition of caustic, without, however, appreciablyimproving the corrosive characteristics of the resulting product.

I have discovered that when treating the raw petroleum residual wax resulting from the aluminum chloridetreatment of such--wax with relatively small amounts of alkali or alkalin'e earth metal plumbite, such as sodium-, potassiumcalcium-, barium-, or the-like plumbite, deleterious corrosion imparting substances are substantially eliminated from the product This hydrochloric acidity of the product'may be reaction product in the usual manner and titrating the hydrochloric acid in the distillate with The invention is applicable to petroleum resid- I ual waxes both of the oil-free and oil-containing type, such as micro-crystalline waxes, petrolatum and others.

Within the preferred embodiment of my lnventuresmay vary, dependingupon type and characteristics of wax used. In the majority of cases, however, temperatures in excess of 150 F. and preferably in excess of 180 F; give satisfactory results. The heating'should be carried out atleast at the melting point of the wax and' preferably at least at 150 F. and for best results at leastat 180 F. and below the decomposition point of the wax. If desired, an alcoholic plumbite solution may be used. The duration of heating is dependent upon the time required for completion of the reaction, 1. e., elimination of corrosive sub. stances that are determinable in the form of asstandard causttic solution. Ordinarily, reaction is completed in a relatively short period of time.

The concentration ofplumbite is notcritical. The necessary amount of plumbite is ordinarily determined by the amount of hydrochloric acidity ascertained for the raw ,material to be treated. For satisfactory results it is recommended to add an amount ofplumbite in excess of that corresponding to the equivalent weight of predetermined hydrochloric acidity of the aluminum chloride treated stock. \After the'completion of the sodium plumbite treatment the resulting reaction product is then washed and distilledin the nor m1 m n 7 Within the preferred-scope of my invention a sodiumplumbite solution may be prepared. for instance, by dissolving lead oxide (PbO) in an aqueous" causttic alkali solution of suitable trength to obtain a substantially saturated so;- dium plumbite solution. s For satisfactory results, for instance, 6 to 7% of PbO may be added to a solution of 12.5% NaOH in water. The. solubility of PhD in caustic soda of the above strength is usually between 2 and 4%, depending onthe grade of'PbQ used, so 'thatin this case there is asurplus 'of PbQ" present and-the sodium plumbite.

solution for-media saturated under the conditions stated.

It is of advantage to use a surplus of the plumb:

ite solution, which after use may be drawn off and again brought up to its approximate original strength by addition of caustic and PhD till the solution becomes finally saturated with NaCl, the same being then discarded or suitably worked up.

Within, the purview of my invention, it isin many cases of advantage to use theresidual wax in a suitable solvent solution. Any of the conventional solvents used forlwax treatments, such as naphtha or the like, may be used for thi purpose. when proceeding in thi mannerfthe' so diumplumbite reaction may be carried on at temperaturesdower than 150? F. dependingupon particula "considerations'or conditions. Q e tollowing examples are furnished by way l tr o dnotjnf"limi i n: t:

, Example I An aluminum chloride treated amorphous wax having a melting point of about 135 1". was analyzed for hydrochloric acidity and found to concertainable hydrochloric acidity of the product. in ch ci y in m n equivalent to 1-90 mgs. KOH per gram. This product was dissolved in naphtha to the extent of a 50% solution and treated for half an hour between 150 and 180 F. with a saturated caustic soda. sodium plumbite solution prepared by dissolving 12.5% NaOH in water and adding thereto about 7% or PbO. The amount of caustic soda sodium-,plumbite solution added was 10% oi the wax in solution; There. suiting product was permitted to settle and was then washed with water to remove substantially;

all free sodium plumbite andtwasthenisteam,

equivalent weight of predetermined hydrochloric acidity of such wax, and thereafter recovering from the reaction product a petroleum residual wax substantially free from such aluminum chloride induced corrosive substances.

3. In the method of refining a petroleum residual .wax'whiohhas been subjected to-aluminum chloride treatment andcontaining'jas a result or such treatment aluminum chloride induced corrosive substances, the improvement comprising reacting such vwax in organic solvent solution distilled for removal of solvent remain;- .{glwith a substantially saturated aqueous solution of i a plumbite selected from the group consisting of mg product, titrated for acidity (H01) showed an" amount of hydrochloric acidityequivalent 1201002' mg KOH per gran 1;: ,1 i

A petrolatum stock of a melting p oint'("still-" 120 F. resulting from the aluminum chloride: treatment of raw petrolatum stock andhaving a predetermined hydrochloric acidity in excess of 1.5 mgs. KOH pergram was suhiected tothifsame plumbite treatment and un er; substantially the same reaction conditionsas tolsolvent, timegteme perature and amounts setv forth in Example I. The product, remaining aiterremoval of, solvent, was found to be substantially n e iromw'hydrochloricacidity. V I p 5w l r I, .1; A saturated caustic soda scdiumplumbitesm lution prepared as set forth in Example I was suspended in a molten aluminum chloride-treated petrolatum stock or the 1 characteristics including acidity set" forth'in Example II; -The s'uspension was heated for'one-halthourbetween 150 Fpand 180 F. The resultingproduct was then filtered while in molten condition. The' fil trate, tested for acidity (H01) showed'substantial freedom from hydrochloric acidity. Y i

The' foregoing specific description is for purposes of illustration and note! limitation' and it is therefore my intention that the invention be limited only by the appended claims or their equivalents wherein I have endeavored to claim broadly all inherent novelty.

1; In the method orrefining a' r pe'troleum residual wax which has been subjected to aluminum chloride treatment and containing-as a j result of suchtreatment alumin mjchlonce induced corrosive substances, the improvement comprising reacting such wax with a relativelyjsmall amount {or a plumbiteselected fromfthe jgroup consisting V of alkali and alkaline earthijrnetal b l bites, andi eco erine from: the reafction mix a petroleum residual waxsubstantianyfiree trom such aluminumflchloride. i duced 'corrosivesube stances. V

zm v sidual wax which has v been subjected i i-aluminum chloride treatment and containing as aresult of such treatment, aluminum chl oridej mduced cor; rosive substances, the I ir'nprovement, comprising reacting such wax while in'molten condition with a substantially saturated -adueoui1j$ol1itioh f or plumbite selected from "the group consisting} of alkali and alkaline earth metal plum bites lsaid plumbite being. present in said aqueous solution in amount in excess of that corresponding tothe alkali-and alkaline-searth metal plumbites, said plumbite being present in said aqueous solution in amount in excess of that corresponding to the equivalent, weight of predetermined hydrochloric ride induced corrosive substances.

- 4. In themethod of refining a petroleum'residual wax, the improvement in accordance with claim 3 in which said wax is reacted with said plumbite solution at a temperature in excessvof 150F.

5.'In the method of refining a petroleum residual wax which has been subjected to aluminum chloride treatment and containing as a result of suchtreatment aluminum chloride induced corrosive; substances, the improvement comprising finely dispersing an aqueous caustic alkali solution of alkali metalplumbite in such wax while in molten condition, said plumbite being present 5 in saidaqueous solution in amount in excess of that corresponding to the equivalent weight of predetermined hydrochloric acidity of such wax, reacting said plumbite solution with said wax at above the melting point of said wax, thereafter separating the aqueous phase from the waxy phase, and recovering 'from said waxy phase a petroleu nrresidual wax substantially free from such aluminum chloride induced corrosive substances.

6. In the method or refining a petroleum residual wax which has been subjected to aluminum chloride treatment and containing as aresult of such treatment; aluminum chloride induced corrosive substances-the improvement comprisingreacting ata temp rature of at least l50"-'F. a solution of suchrwaxain an organic solvent with h a saturated aqueous caustic alkali solution of alethodtof petroleumlires hair metal plumbitesaid plumhite being present in said aqueous solution in amount in excess of that corresponding .to the equivalent weight of predetermined hydrochloric acidity of such wax,- separating the reaction product into an aqueous phase and a solventphase, removing thesolvent from the solvent phase and recovering from the residue of the solvent phase a petroleum residual wax substantially free from aluminum chloride induced corrosive substances. '7, In the. method of refining a petroleum residual wax, the improvement, in accordance vwith claim 6 in which said aqueous plumbite solution is a sodium plumbite solution and in whichsaid organic, solvent is naphtha. 

